/Engine/Plugins/Interchange/Runtime/Source/Import/Public/MaterialX/MaterialXUtils/MaterialXSurfaceShaderAbstract.h
Add an attribute to a shader node from the given MaterialX input, only floats and linear colors are supported for the moment
true if the attribute was successfully added
bool AddAttribute ( MaterialX::InputPtr Input, const [FString](API\Runtime\Core\Containers\FString) & InputChannelName, [UInterchangeShaderNode](API\Plugins\InterchangeNodes\UInterchangeShaderNode) * ShaderNode ) const